Hi,
We wish to implement an ESX solution on our organization.
We want the ESX will be on Server with 2 dual core CPU's.
When installing new virtual machine on this kind of server, does the oprating sysytem will recognize 4 CPU's? (2 For each dual core CPU)? ?
Also - are the cores -Dedicated- to that virtual machine? which means that other virtual machine sitting on the same ESX server will not be able toi
use them , when both of the mahcines work at the same time?
I'm asking that because when I use VMWARE server on an HW of 2 Dual core CPU, at the guest virtual machine, one that I configured to use 2 CPU's- I see only 2 cpu's.
(Instead on the real server that the OS see 4 CPU)
Can you please help?
Thank you,
Rafi Abarjeel
Siano Mobile Silicon
it@siano-ms.com
Hi,
We wish to implement an ESX solution on our
organization.
We want the ESX will be on Server with 2 dual core
CPU's.
When installing new virtual machine on this kind of
server, does the oprating sysytem will recognize 4
CPU's? (2 For each dual core CPU)? ?
When you set up the VM, you can tell it how many CPUs you want. With 2 dual-core physical CPUs in the host ESX server, you can give the VM up to 4 CPUs.
Also - are the cores -Dedicated- to that virtual
machine? which means that other virtual machine
sitting on the same ESX server will not be able toi
use them , when both of the mahcines work at the same
time?
You can also set this, although I never have. You can set a VM to run on specific physical CPUs if you want. That VM can have exclusive rights to that CPU if you want.
One other thing. Having multiple virtual CPUs in a VM does not always the performance increase you would get if you added a second CPU to a physical machine. in some cases, performance could go down.
With a single virtual CPU, a thread needs to wait for ANY of the 4 physical CPUs in your system to become available before it can process the thread. With 2 virtual CPUs in a VM, the VM must wait for 2 physical CPUs to become available AT THE SAME TIME before it can process the threads. With 4 virtual CPUs, ALL of the physical CPUs in your host server must be available at the same time before the VM can process anything. At that point, why even have a virtual machine?
virtual cpu's are independent of the physical cpu.
As stated above esx will be able to present 4 cpus to your virtual guest 2 dual core cpus= 4 virtual cpus.
The hypervisor will mask the underlying hardware.
aas the previuous reply first present 1 vcpu and add another only if needed. Multiple vcpus need to wait for 2 free cpu's to provide a guest cpu time.